A186344 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) after g(j) when f(i)=g(j), where f and g are the pentagonal numbers and the octagonal numbers. Complement of A186345.
2, 3, 5, 7, 8, 10, 12, 13, 15, 17, 19, 20, 22, 24, 25, 27, 29, 30, 32, 34, 36, 37, 39, 41, 42, 44, 46, 48, 49, 51, 53, 54, 56, 58, 59, 61, 63, 65, 66, 68, 70, 71, 73, 75, 77, 78, 80, 82, 83, 85, 87, 88, 90, 92, 94, 95, 97, 99, 100, 102, 104, 106, 107, 109, 111, 112, 114, 116, 118, 119, 121, 123, 124, 126, 128, 129, 131, 133, 135, 136, 138, 140, 141, 143, 145, 147, 148, 150, 152, 153, 155, 157, 158, 160, 162, 164, 165, 167, 169, 170
Offset: 1
Keywords
Examples
First, write 1..5...12....22..35..... (pentagonal) 1....8....21........40.. (octagonal) Then replace each number by its rank, where ties are settled by ranking the pentagonal number after the octagonal: a=(2,3,5,7,8,10,12,13,15,....)=A186344 b=(1,4,6,9,11,14,16,19,21,...)=A186345.
Programs
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Mathematica
(* adjusted joint ranking; general formula *) d=-1/2; u=3/2; v=-1/2; w=0; x=3; y=-2; z=0; h[n_]:=-y+(4x(u*n^2+v*n+w-z-d)+y^2)^(1/2); a[n_]:=n+Floor[h[n]/(2x)]; k[n_]:=-v+(4u(x*n^2+y*n+z-w+d)+v^2)^(1/2); b[n_]:=n+Floor[k[n]/(2u)]; Table[a[n], {n, 1, 100}] (* A186344 *) Table[b[n], {n, 1, 100}] (* A186345 *)